Portable and collapsible stacking bins or crates



March 12, 1968 c. c. AVERILL 3,372,829

PORTABLE AND COLLAPSIBLE STACKING BINS OR CRA Filed May 18, 1964 2 Sheets-Sheet l HIHH INVENTOR. Char/e; C. A Ve/fl/ A ORN c. c. AVERILL 3,372,829 EOE TABLE AND C OLLAPSIBLE STACKING BINS OR CRATES 7 March 12, 1968 Filed may 18, 1954 2 Sheets-Sheet 2 g illlllllllllilo,

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United States Patent 3,372,829 PORTABLE AND COLLAPSIBLE STACKING BINS OR CRATES Charles C. Averill, Albion, Mich., assignor to Union Steel Products Company, Albion, Mich. Filed May 18, 1964, Ser. No. 368,139 14 Claims. (Cl. 220-6) This invention relates to portable and collapsible stacking bins or crates.

The main objects of this invention are:

First, to provide a light weight collapsible bin having parts which interlock within each bin when erected and between stacked bins to reinforce the individual bins and stacks so that substantial loads may be contained in the bins, and so that the bins may be stacked in a bank for storing or dispensing items.

Second, to provide a collapsible wire mesh bin or crate made of relatively light or small gauge wire and rod stock and having sectional, folding front walls that can be interlocked with the end walls of the bins to form transportable containers that can be moved by fork lift trucks and can be stacked in banks and the contents made accessible by opening one or more of the front Wall sections.

Third, to provide a light weight wire mesh bin having a back wall hingedly connected to a base, and end walls hingedly connected to the ends of the back wall and the base having depending feet connected to mesh reinforcing rods to raise the bin or crate off of the floor for lifting by a fork truck, the feet being arranged to nest and stack on lower bins in mutually reinforcing engagement.

Fourth, to provide a wire mesh bin having the base and hinged walls described and sectional front wall, the lower section of the front wall being hingedly connected to the base and the upper section of the front wall being hingedly connected to the lower section.

Fifth, to provide a bin or crate having these structural advantages in which a superimposed crate serves to hold the collapsible walls of a lower crate in erected position.

Objects relating to details and economies of the invention will appear from the description to follow. The invention is defined and pointed out in the claims.

A preferred embodiment of the invention is illustrated in the accompanying drawing, in which:

FIG. 1 is a front perspective view of crates or containers embodying my invention mounted upon the truck, the walls of the crates being mainly broken away and a lower portion only of the superimposed crate being shown.

FIG. 2 is a fragmentary end elevational view of parts of two crates embodying my invention disposed in stacked relation, the front wall for the lower crate not being shown.

FIG. 3 is an enlarged fragmentary vertical section with an upper section of the front wall shown in collapsed position by full lines, the collapsed front wall being shown partially opened by dotted lines.

FIG; 4 is an end view of the front wall in collapsed position and the collapsed rear and end wall in partially collapsed position illustrating the relation of the parts when in collapsed position.

FIG. 5 is an enlarged fragmentaryview illustrating details of the lock on a line corresponding to line 5-5 of FIG. 3.

FIG. 6 is a fragmentary view on a line corresponding to line 6-45 of FIG. 7 illustrating details of the leg structure and mounting thereof. I

FIG. 7 is a fragmentary view on a line corresponding to line 7-7 of FIG. 6 showing further details of the leg structure.

FIG. 8 is a side elevational view, mainly conventionalized, illustrating two stacks of receptacles embodying my invention substantially mounted on a truck.

3,372,829 Patented Mar. 12, 1968 In the accompanying drawings only parts of the walls are illustrated mainly in conventional form as the structural details thereof form no part of my invention and such structures which are commonly formed of wire stock are known in the art. However, it should be understood that the accompanying drawings are not intended to illustrate the parts in commercial dimensions and in some of the figures parts of the walls are conventionally shown.

The bottom unit comprises a rectangular frame designated by the numeral 1 and includes side members 2 and end members 3 which are fixedly connected and in commercial practice are desirably formed of a single piece of rod stock. The joined ends of the stock used are illus trated at 4, see FIG. 1.

The ends of the bottom 5 are welded or otherwise se cured to the bottom frame side and end members. The bottom includes pairs of laterally spaced rods 6 of rod stock which extend from end to end of the bottom and are fixedly secured to the end members 3 of the bottom. It should be understood that these crates or containers vary in size and that they are not necessarily of greater length than width but those having greater length than width are most common.

The frame of the rear wall designated by the numeral 7 comprises bottom frame member 8, top frame member 5! and end frame member 10, desirably formed of a single piece of rod stock. The rear wall panel designated by the numeral 11 is formed of wire strands which commonly are substantially the same as the bottom panel. A frame strut or reinforcing rod 12 is disposed on the inner side of the wall unit 11 in spaced parallel relation to the bottom and top frame members and welded at its ends to the end member 10.

The end walls designated generally by the numeral 13 are duplicates and they comprise border frames 14 formed of rod stock, the upright portions being'connected by the struts 15 which perform the same function as the rod 12 connecting the end members of the rear wall frame. The end walls include wire grid-like members 16 fixedly secured to the end frame 17. The top members 18 of the end wall frames have intermediate portions 19 thereof upwardly offset providing oppositely facing shoulders 20 which are spaced inwardly from the front and rear edges of the end walls. These upwardly offset portions are an important factor in the stacking of the crates. i l

In the accompanying drawings only two crates or containers are illustrated in stacked relation but it should be understood that in practice several of the crates may be disposed in stacked relation and that these crates or containers vary in size. However, it is desirable that they be such size that they may be manually manipulated. The hinging connection for the rear wall to the bottom and for the end walls to the rear wall are desirably in the form of coiled wire which is conventionally shown in most of the figures, but see FIG. 4.

In the embodiment illustrated the front wall bottom section 21 and the top section 22 each comprise a frame of rod stock 23 and grid-like wall portions 24, only a portion of which are illustrated in FIG. 1. The bottom of the front wall section 21 is hingedly secured to the front member of the bottom frame by means of the coil 25 and the upper front wall section 22 is hingedly secured to the bottom section 21 by means of the coil 26, portions of which are conventionally shown in FIG. 1. These front wall sections are provided with bolt means disposed with one at the ends of each section, see FIG. 1.

The bolt means comprises bolt support members 27 having outwardly projecting outer and inner arms 28 and 29, these bolt support members are secured to portions 30 of the wall members of the front wall sections, see FIG. 5. The bolts 31 are provided with loop-like handpiece portions 32 which are of substantial size to facilitate grasping and also providing Weight so that when the handpieces 32 are released the bolt handpieces swing down, as is illustrated in FIG. 1, and as shown by full lines in FIG. 3. The manipulating position of these bolts is illustrated by dotted lines in FIG. 5. The bolt is provided with a lug 33 which, in the embodiment illustrated, projects upwardly from the bolt when the bolt is in released position as shown in full lines.

The inner arms 29 of the bolt support member are provided with elongated openings 34 through which the bolts are disposed, these openings being dimensioned to permit the lugs to pass therethrough when the handpiece is swung to substantial right angular relation to the wall. This is a desirable feature as it permits an outward pull on the wall when the bolt is in disengaged position. The inwardly projecting portions of the handpieces 32 serve as stops to limit the longitudinal movement of the bolt. The keepers 35 are also desirably formed of rod stock and are rigidly attached to the front upright members 13 of the end wall frames. With this arrangement the front wall can be opened and closed with like crates in stacked position, as is conventionally illustrated in the drawings.

The embodiment of my invention illustrated is designed to be positioned on a wheeled truck designated generally by the numeral 36 and which has a rectangular frame comprising side members 37, end members 38 of inwardly and upwardly facing angled section, the joints for these side and end members not being illustrated, they are shown as unitary. The frame is provided with rear wheels 39 and front wheels 40, the front wheels being of the caster type.

The legs designated generally by the numeral 41 comprise body portions 42, see FIGS. 6 and 7, having inwardly projecting portions 43 disposed on the undersides of the bottom members 6 and welded thereto. The legs have forwardly projecting downwardly facing portions 44 engageable with the top members of the end frames or with the frame members of the truck, as illustrated in FIGS. 1, 2, and 8.

In the embodiment illustrated each leg includes two sruct members 47 which are welded to the upright portions of the legs with their upper ends disposed on the inner sides of the base members 6 and welded thereto, as indicated at 48 in FIG. 7. These brace members are conformed to fittingly engage the upright portions and the forwardly projecting portions of the legs and are welded to such portions as is indicated at 49, see FIGS. 6 and 7. Wih this arrangement the legs can be formed of relatively light stock and are strong and rigid. It should be understood that this is an important feature inasmuch as the structures embodying this invention are, as stated, designed to be made of such size that they can be manually manipulated to stacking and unstacking position and translated as may be desired.

An important feature of the invention is that the stacked receptacles or containers, as illustrated in FIG. 1, can be opened when in stacked position for the insertion or removal of material and when arranged in two stacks, as shown in FIG. 8, the front portions are disposed to face outwardly. That arrangement is not illustrated as the parts are shown conventionally in FIG. 8, however, it is a highly desirable feature. With the end walls provided with the upwardly offset portions providing laterally facing portions 20 the stacked upper receptacles cannot shift laterally on the lower receptacles of the stack and that is also an important feature.

I have illustrated and described my invention in a highly practical commercial embodiment thereof. I have not attempted to illustrate possible structural modifications as it is believed this disclosure will enable those skilled in the art to embody my invention as may be desired.

As stated, the accompanying drawings illustrate some of the parts conventionally as the details thereof form no part of my present invention. The containers of the invention are of light weight for easy handling by manual means or power operated lift trucks but they are not designed for shipment of heavy loads over long distances and bumpy roads. The interlocking engagement between the parts of the containers permit them to retain relatively heavy loads when stacked or when moved short distances as between filling, storage and contents dispensing locations in a plant.

Having thus described the invention, what is claimed as new and desired to secure by Letters Patent is:

1. In a crate or container, the combination of a bottom unit comprising a rectangular frame of rod-like stock having integral front, rear and end members, a rear wall unit comprising a rectangular frame of rod-like stock and having integral bottom, end and top members, the bottom member of said rear wall unit being hingedly connected to the rear member of said bottom frame, end walls, each comprising a rectangular frame of rod-like stock and having integral bottom, side and top members, the top members having intermediate portions thereof of substantial length upwardly offset thereby providing the top members with laterally spaced laterally facing shoulders, the rear side members of said end wall frames being hingedly connected to the end uprights of said rear Wall frame, the said connections permitting the collapsing of the end walls on said rear wall, the hinge connection for said rear wall to said bottom unit permitting the collapsing thereof with the end wall collapsed relative thereto upon said bottom unit, a front wall unit comprising sections, each section including rectangular frame members of rod-like stock including unitary bottom, top and end members, the bottom member of the lower of said front wall sections being hingedly connected to the front frame member of the bottom, adjacent longitudinal frame members of said front wall sections being hingedly connected to each other, the connections for the bottom front wall member to the bottom being such as to permit collapsing of the front wall unit upon the bottom, the said rear and end walls when the end walls are in collapsed position being collapsible upon the front wall unit when it is in collapsed position upon the bottom, and legs disposed at the ends of and fixedly mounted on said bottom unit and having downwardly facing recesses supportedly engageable with the top members of the end walls when they are in erected position, said legs being spaced to laterally engage said upwardly projecting portions of said end Wall frames, said front wall sections and said end walls having coacting bolts and keepers for holding the front wall sections in erected position while permitting the sections being successively opened to afford access to the contents of the crate with like crates in stacked position.

2. In a crate or container, the combination of a bottom unit comprising a rectangular frame of rod-like stock having integral front, rear and end members, a rear wall unit comprising a rectangular frame of rod-like stock and having integral bottom, end and top members, end walls, each comprising a rectangular frame of rod-like stock and having integral bottom, side and top members, the top members having intermediate portions thereof of substantial length upwardly offset thereby providing the top members with laterally spaced laterally facing shoulders, the rear side members of said end wall frames being connected to the end uprights of said rear wall frame, a front wall unit comprising sections, each section including rectangular frame members of rod-like stock including unitary bottom, top and end members, the bottom member of the lower of said front wall sections being hingedly connected to the front frame member of the bottom, adjacent longitudinal frame members of said front wall sections being hingedly connected to each other, the connections for the bottom front wall member to the bottom being such as to permit collapsing of the 5. front wall, and legs disposed at the ends of and fixedly mounted on said bottom unit and having downwardly facing recesses supportedly engageable with the top members of the end walls when they are in erected position, said legs being spaced to laterally engage said upwardly projecting portions of said end wall frames, said front Wall sections and said end walls having coacting bolts and keepers for holding the front wall sections in erected position while permitting the sections being successively opened to afford access to the contents of the crate with like crates in stacked position.

3. In a crate or container, the combination of a bottom unit comprising a rectangular frame of rod-like stock having integral front, rear and end members, a rear wall unit comprising a rectangular frame of rod-like stock and having integral bottom, end and top members, the bottom member of said rear wall being hingedly connected to the rear member of said bottom frame, end walls, each comprising a rectangular frame of rod-like stock and having integral bottom, side and top members, the rear side members of said end wall frames being hingedly connected to the end uprights of said rear wall frame, the said connections permitting the collapsing of the end walls on said rear wall, the hinge connection for said rear wall to said bottom unit permitting the collapsing thereof with the end Wall collapsed thereon relative thereto upon said bottom unit, a front wall unit comprising sections, each section including rectangular frame members of rod-like stock including unitary bottom, top and end members, the bottom member of the lower of said front wall sections being hingedly connected to the front frame member of the bottom, adjacent longitudinal frame members of said front wall sections being hingedly connected to each other, the connections for the bottom front Wall member to the bottom being such as to permit collapsing of the front Wall unit upon the bottom, the said rear and end walls when the end walls are in collapsed position being collapsed upon the front wall unit when it is in collapsed position upon the bottom, said front Wall sections and said end walls having coacting bolts and keepers for holding the front wall sections in erected position while permitting the sections being opened to afford access to the contents of the crates.

4. In a crate or container, the combination of a bottom unit comprising a rectangular frame of rod-like stock having integral front, rear and end members, a rear Wall unit comprising a rectangular frame of rod-like stock and having integral bottom, end and top members, the bottom member of said rear wall unit being hingedly connected to the rear member of said bottom frame, end walls, each comprising a rectangular frame of rod-like stock and having integral bottom, side and top members, the rear side members of said end wall frames being hingedly connected to the end uprights of said rear wall frame, the said connections permitting the collapsing of the end walls on said rear wall, the hinge connection for said rear wall to said bottom unit permitting the collapsing thereof with the end wall collapsed thereon relative thereto upon said bottom unit, a front wall unit comprising collapsed connected sections, the bottom member of the lower of said front wall sections being hingedly connected to the front frame member of the bottom, adjacent longitudinal frame members of saidfront wall sections being hingedly connected to each other, the connections for the bottom front wall member to the bottom being such as to permit collapsing of the front wall unit upon the bottom, said front Wall sections and said end walls having coacting bolts and keepers for holding the front wall sections in erected position while permitting the sections being opened to afford access to the contents of the crates.

5. A crate or container comprising a bottom unit, a rear wall hingedly connected to the rear edge of said bottom unit, end walls hingedly connected at their rear ends to the ends of said rear wall to be collapsed relative thereto and disposed when in erected position with their bottom edges in supporting engagement with said bottom unit, said end walls having upwardly projecting laterally facing shoulders on their upper edges spaced inwardly from the front and rear ends of said end walls, the hinge connections for said rear wall to said. bottom and said end walls to said rear wall permitting collapsing thereof in superimposed relation to said bottom unit, a front wall unit comprising hingedly connected sections, the lower section being hingedly connected to said bottom unit at the front edge thereof, the hinged connection for the upper of said front wall section being such to permit outward opening movement of the upper section and being such as to permit the collapsing of the front Wall sections upon the bottom unit, and legs fixedly mounted on the bottom unit and having portions supportedly engageable with the end walls when in erected position and spaced to laterally engage said upwardly projecting portions of said end Walls, said front Wall sections and said end walls having coacting means for holding the front Wall sections in erected position while permitting the front wall sections being successively opened for access to the contents of the crates when like crates are in stacked position.

6. A crate or container comprising a bottom unit, a rear wall hingedly connected to the rear edge of said bottom unit, end Walls hingedly connected at their rear ends to the ends of said rear Wall to be collapsed in lapping relation thereto and disposed when in erected position with their bottom edges in supported engagement with said bottom unit, the hinge connections for said rear wall to said bottom and said end walls to said rear Wall permitting collapsing thereof in superimposed relation to said bottom unit, a front Wall unit comprising hingedly connected sections, the lower section being hingedly connected to said bottom unit at the front edge thereof, the hinged connection for the upper of said front wall sections to the lower section being such to permit outward opening movement of the upper section and to permit the collapsing of the front wall sections upon the bottom unit, said front wall sections and said end walls having coacting means for holding the front wall sections in erected position and permitting the front wall sections being successively opened for access to the contents of the crates when like crates are in stacked position.

7. A crate or container comprising a bottom unit, a rear Wall hingedly connected to the rear edge of said bottom unit, end walls hingedly connected at their rear ends to the ends of said rear Wall to be collapsed relative thereto and disposed when in an erected position with their bottom edges in supported engagement with said bottom unit, said end walls having upwardly projecting laterally facing shoulders on their upper edges spaced inwardly from the front and rear ends of said end walls, the hinge connections for said rear wall to said bottom and said end walls to said rear Wall permitting collapsing thereof in superimposed relation to said bottom unit, a front wall unit hingedly connected to said bottom unit at the front edge thereof, and legs fixedly mounted on the bottom unit and having portions supportedly engageable with the end walls when in erected position and spaced to laterally engage said upwardly projecting portions of said end walls, said front Wall and said end Walls having coacting means for holding the front wall in erected position while permitting the front Wall being successively opened for access to the contents of the crates when like crates are in stacked position.

8. A crate or container comprising a bottom unit, a rear wall hingedly connected to the rear edge of said bottom unit, end walls hingedly connected at their rear ends to the ends of said rear wall to be collapsed relative thereto and disposed when in erected position with their bottom edges in supporting engagement with said bottom unit, the hinge connections for said rear Wall to said bottom and said end walls to said rear Wall permitting collapsing thereof in superimposed supported relation to said bottom unit, a front wall unit hingedly connected to said bottom unit at the front edge thereof, said front wall and said end walls having coacting means for holding the front wall in erected position while permitting the front Wall to be opened for access to the contents of the crates when like crates are in stacked position.

9. A crate or container comprising a bottom unit, a rear wall supportedly and hingedly connected to the rear edge of said bottom unit, end walls hingedly connected to the rear wall and having upwardly projecting laterally facing shoulders on their upper edges spaced from the front and rear ends thereof, a front wall unit comprising swingably connected sections, the lower of which is swingably connected to said bottom unit, the connections for said front wall sections permitting the outward swinging movement of an upper section relative to a section to which it is swingably connected, the lower front wall section being adjustably connected to the bottom unit permitting collapsing of the front wall unit thereon, said bottom unit being provided with legs supportedly engageable with said end walls when they are in erected position, the legs being spaced to coact with said upwardly projecting portions on said end walls to prevent lateral shifting of a superimposed container relative to the container on which it is superimposed, said front wall and said end walls having coacting means for holding the front wall sections in erected position while permitting the front wall sections being successively opened to provide access to the contents of the crate or container when it is in stacked position,

10. A crate or container comprising a bottom unit, a rear wall supportedly and hingedly connected to the rear edge of said bottom unit, end walls hingedly connected to the rear wall, a front wall unit comprising swingably connected sections, the lower of which is swingably connected to said bottom unit, the connections for said front Wall sections permitting the outward swinging movement of the upper section relative to the section to which it is swingably connected, the lower front wall section being adjustably connected to the bottom unit to permit collapsing of the front wall unit thereon, said bottom unit being provided with legs supportedly engageable with said end walls when they are in erected position, said front Wall and said end walls having coacting means for holding the front wall sections in erected position and permitting the front wall sections being successively opened to provided access to the contents of two or more stacked containers.

11. A crate or container comprising a bottom unit provided with legs, a rear wall supportedly connected to said bottom unit, end walls connected to the rear wall at the ends thereof and having upwardly projecting laterally facing shoulders on their upper edges, said legs being engageable upon said end walls and being laterally spaced to coact with said shoulders on said end walls so that lateral shifting of a superimposed container relative to the container on which it is superimposed is prevented, and a front Wall unit hingedly connected to said bottom unit, said front wall unit and said end walls having coacting means for releasably holding the front wall in closed position.

12. A crate or container comprising a bottom unit provided with legs, a rear wall supportedly connected to said bottom unit, end walls hingedly connected to the rear wall at the ends thereof and having spaced upwardly projecting portions on their upper edges, said legs being engageable upon said end walls and being laterally spaced to coact with said shoulders on said end walls so that lateral shifting of a super-imposed container relative to the container on which it is superimposed is prevented, and a front wall unit hingedly connected to said bottom unit and having coupling means releasably engageable with said end walls for holding the front wall in closed position.

13. The combination with a wheeled truck having a rectangular frame including fixedly connected side and end members, of a crate comprising a base member frame having laterally spaced leg supporting members fixedly secured thereto, and legs, each comprising a body portion of relatively fiat sheet stock conformed to provide an upright portion terminating at its upper end in an inwardly projecting flange disposed on the undersides of and fixedly secured to said leg supporting members and having outwardly projecting downwardly facing portions at its lower end engageable with said truck frame, and strut members disposed in laterally spaced relation to each other with their upper ends on the sides of and fixedly secured to said leg supporting members and with their lower ends in supporting engagement with said outwardly projecting portions of said legs and fixedly secured thereto, and with their rear edges fixedly secured to the upright portions of the legs.

14. The combination with a wheeled truck having a rectangular frame including fixedly connected side and end members, of a crate comprising a base member frame having laterally spaced leg supporting members fixedly secured thereto, and legs, each comprising a body portion of relatively fiat sheet stock conformed to provide an up right portion terminating at its upper end in an inwardly projecting flange disposed on the undersides of and fixedly secured to said leg supporting members and having outwardly projecting downwardly facing portions at its lower end engageable with said truck frame, and strut members disposed in laterally spaced relation to each other with their upper ends fixedly secured to said leg supporting members and with their lower ends in supporting engagement with said outwardly projecting portions of said legs and fixedly secured thereto, and with their rear edges fixedly secured to the upright portions of the legs.

References Cited UNITED STATES PATENTS 2,660,328 1 1/ 1953 Averill 220--6 2,695,724 11/1954 Averill 220-19 2,780,381 2/ 1957 Coit 220-6 2,781,936 2/ 1957 Bitney 220-97 2,806,623 9/1957 Beckner 2206 2,916,293 12/1959 Lang 22097 3,137,250 6/ 1964 Hutchinson 220-6 FOREIGN PATENTS 1,227,059 2/ 1960 France.

RAPHAEL H. SCHWARTZ, Primary Examiner.

THERON E. CONDON, Examiner. 

1. IN A CRATE OR CONTAINER, THE COMBINATION OF A BOTTOM UNIT COMPRISING A RECTANGULAR FRAME OF ROD-LIKE STOCK HAVING INTEGRAL FRONT, REAR AND END MEMBERS, A REAR WALL UNIT COMPRISING A RECTANGULAR FRAME OF ROD-LIKE STOCK AND HAVING INTEGRAL BOTTOM, END AND TOP MEMBERS, THE BOTTOM MEMBER OF SAID REAR WALL UNIT BEING HINGEDLY CONNECTED TO THE REAR MEMBER OF SAID BOTTOM FRAME, END WALLS, EACH COMPRISING A RECTANGULAR FRAME OF ROD-LIKE STOCK AND HAVING INTEGRAL BOTTOM, SIDE AND TOP MEMBERS, THE TOP MEMBERS HAVING INTERMEDIATE PORTIONS THEREOF OF SUBSTANTIAL LENGTH UPWARDLY OFFSET THEREBY PROVIDING THE TOP MEMBERS WITH LATERALLY SPACED LATERALLY FACING SHOULDERS, THE REAR SIDE MEMBERS OF SAID END WALL FRAMES BEING HINGEDLY CONNECTED TO THE END UPRIGHTS OF SAID REAR WALL FRAME, THE SAID CONNECTIONS PERMITTING THE COLLAPSING OF THE END WALLS ON SAID REAR WALL, THE HINGE CONNECTION FOR SAID REAR WALL TO SAID BOTTOM UNIT PERMITTING THE COLLAPSING THEREOF WITH THE END WALL COLLAPSED RELATIVE THERETO UPON SAID BOTTOM UNIT, A FRONT WALL UNIT COMPRISING SECTIONS, EACH SECTION INCLUDING RECTANGULAR FRAME MEMBERS OF ROD-LIKE STOCK INCLUDING UNITARY BOTTOM, TOP AND END MEMBERS, THE BOTTOM MEMBER OF THE LOWER OF SAID FRONT WALL SECTIONS BEING HINGEDLY CONNECTED TO THE FRONT FRAME MEMBER OF THE BOTTOM, ADJACENT LONGITUDINAL FRAME MEMBERS OF SAID FRONT WALL SECTION BEING HINGEDLY CONNECTED TO EACH OTHER, THE CONNECTIONS FOR THE BOTTOM FRONT WALL MEMBER TO THE BOTTOM BEING SUCH AS TO PERMIT COLLAPSING OF THE FRONT WALL UNIT UPON THE BOTTOM, THE SAID REAR AND END WALLS WHEN THE END WALLS ARE IN COLLAPSED POSITION BEING COLLAPSIBLE UPON THE FRONT WALL UNIT WHEN 